Trees and plants play a vital part in our climate and creating the oxygen and water we and other species need for survival.

Where rainfall is high and temperatures constant, as in the area around the equator, rainforests grow. Typically thick and impenetrable, a rainforest supports a large number of species (almost two thirds of the world's birds live in the tropics). The rainforest is a unique habitat in the wet and humid areas of the world, and an important part of the world habitat and climate.

In the rain forest the eco-system is very highly developed and the cycle of water, especially, moving from the soil through plants and then falling again as rain, is key to the long-term survival of the forests, and to the tropics, as we know them.

Tropical rainforests once covered huge areas of South America, Asia and Africa. Clearances by farmers, indigenous peoples, timber companies and mining have reduced the area rain forest dramatically. The longer-term effects of this clearance are not known, but there is concern that it may contribute to world climate change.

New Zealand has temperate rainforests in many areas, the most significant being on the West Coast of the South Island. When you are in the native bush, or rain forest, you can feel the humidity, the dampness that is essential to sustaining the plants and evidence of the water cycle.

Creating the water we need is one of the vital roles trees and plants play in our world. Making your own rainforest helps you to understand this.

You can create a 'rainforest' in miniature, and study how the plants create rainfall from transpiration, the moisture then falls and is absorbed into the soil, drawn up through the roots of the plants, and then lost through transpiration again.

Empty clear plastic container the same diameter as the pot or 2 lengths of wire, plastic bag and a rubber band.

First separately wash the gravel and pebbles.

Add a layer of about 2.5cm (1 inch) of pebbles in the base of your pot, and then 2.5cm (1 inch) of charcoal, followed by 2.5cm (1 inch) of fine gravel.

Place a layer of soil in the pot, just enough so that your plant will be level with the top of the pot when placed on top.

Take the plant out of its container, and add more soil around it to fill the pot and firming gently with your fingers.

Water well.

Holding the empty plastic container upside down, like an umbrella, cover the surface of the pot. Tuck the edges inside the pot.

Or, make two hoops across the pot with lengths of wire and pull a plastic bag over them. Hold the bag around the outside of the top of the pot with a strong rubber band.

In a couple of days you should see moisture form inside the top, or ceiling, of the plastic. This moisture has been transpired by the plants and will fall down, onto the soil and find its way into the plant through the roots - and you have a rainforest!

Remember not to take the plastic cover off, or you will lose the moisture essential to the process.

Our rainforest without the 'umbrella' cover

Your rainforest should last for six months or more. Ours is already a year old.

The compilers and Editor of Bestgardening.com's pages have taken every care, in the time available, to check the information included here as to accuracy and safety, but neither they nor Bestgardening.com Limited can accept liability for any resulting injury, loss, or damage to either property or person whether direct or consequential and howsoever arising. Local conditions, climate and adverse events will affect the relevance and accuracy of information. Bestgardening.com Limited stresses that it is essential to carefully read and follow any information given on manufacturers packaging and/or plant labels.